How to safely cut the top off a box?

[Frederick Skelly]

Guys,
I'd like to get your advice on how to safely cut the top off of a box I want to make. The box will be about 13" long, 6" wide and 3" high. It will be made of 1/2" thick poplar.

I'd like to cut a 1/8" deep groove all the way around the top, then separate it from the bottom with a knife. I think it would be best to cut the 2 long sides first. But I am concerned that the 2 short sides are too short to safely cut the groove.

Any thoughts, references or experience that you can offer will help me stay safe.

I appreciate your help.

Fred

Edit: I could use the bandsaw for this but there's downsides to that too.

[Maurice Mcmurry]

I just use the table saw. Cut number 4 is tricky. I build cases this way.

DSCN1634.jpg IMG_0673.jpg IMG_0674.jpg

[Mike Henderson]

I do that on my table saw. The problem is that one cut will be a bit out of place so you then have to sand the box and opening on a sanding board.

If it's half inch material, I'd cut deeper than 1/8 inch. You can adjust the saw so that you leave a thin piece of wood holding the top and bottom together. Then it's fairly easy to cut with a knife.

You can see an alternate way of cutting the top off here. Scroll down on the page.

As an alternative, I've marked the cut line with a marking gauge and used a Japanese saw to cut each side.

Mike

[Frederick Skelly]

I just use the table saw. Cut number 4 is tricky. I build cases this way.

DSCN1634.jpg IMG_0673.jpg

Thank you!

[Frederick Skelly]

I do that on my table saw. The problem is that one cut will be a bit out of place so you then have to sand the box and opening on a sanding board.

If it's half inch material, I'd cut deeper than 1/8 inch. You can adjust the saw so that you leave a thin piece of wood holding the top and bottom together. Then it's fairly easy to cut with a knife.

You can see an alternate way of cutting the top off here. Scroll down on the page.

As an alternative, I've marked the cut line with a marking gauge and used a Japanese saw to cut each side.

Mike

Thanks Mike. I should have thought to check your website. (I have it bookmarked.)

[Jerry Wright]

I have done this many times. Make a setup jig from a scrap of your side material. Place cut from whatever edge you decide will be against the fence, then adjust groove depth to just a hair from going thru. This is your blade position and depth setup piece. I tape the box completely around the cutoff line. Then I cut three sided, and then shim them a bit to hold position. I then make final cut. You may have a small, but sandable offset. Cutting the top off is always an adventure at first.

[Maurice Mcmurry]

It is a cut I like to use my old 120 volt saw for. I can plug it into my stomp switch and kill the saw with my toe just as the lid detaches.

[Andrew Hughes]

When I make my boxes with a top that matches the base I cut all the joinery first then cuts the parts separately on the bandsaw. Then glue it together.
Before I separate the top from the bottom I also cut grooves for the top and bottom on the router table.
Good Luck

[Lee Schierer]

I cut the two short sides first on my table saw. Then I use painters tape to hold a 1/8" thick piece of scrap in the two cuts making sure the ends of the scrap are not going to be hit by the saw blade. Make the two remaining cuts and you are done.

[Eric Phelps ON]

I did this for the first time not long ago on a machinist style toolchest (20x12x14) with the main case made up of 9mm baltic birch. I "just went for it" knowing that the final cut might get a little interesting, and sure enough I ended up taking a bit of a bite out of the one corner. Next time I do it I'll leave a thin section of material around the entire case keeping the whole thing together and then finish the cut with a ryoba.

[Dave VanDewerker]

When I want to cut off a box top, I cut the two long sides completely thru, then lower the blade to leave just a fraction of an inch on the short sides. I then finish removing the top with either a utility knife or japanese saw and a little bit of final sanding.

[Richard Coers]

I cut within 1/64" of making a through cut on the table saw. I run a box cutter around to seperate the top and bottom. I don't worry about it splintering a little bit since I break the edge pretty hard on the inside.

[glenn bradley]

I through-cut. I make spacers like so.

Jewelry Boxes 20220423 (57).jpg

The 'tongue matches the saw kerf exactly. I clamp a backer for the first cut (obviously no spacer yet) and cut just a bit deeper than the side is thick; a through-cut.

Jewelry Boxes 20220423 (56).jpg

Then tape a spacer in that cut and rotate. The first cut allows the blade to clear so there are no tear out concerns.

Jewelry Boxes 20220423 (58).jpg

Rinse and repeat. Don't be shy with the tape. You do not want things shifting mid cut. I often also protect the top or bottom that rides against the fence with a bit of tape as well if the box has already had finish applied.

Jewelry Boxes 20220423 (59).jpg

Jewelry Boxes 20220423 (101).jpg

[Frederick Skelly]

Thank you everyone!
Glenn, the pics really help.Thanks,

[Maurice Mcmurry]

I am going to try the spacers and tape next time.